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Minimum Retroreflectivity Levels for Traffic Signs New MUTCD Criteria

Minimum Retroreflectivity Levels for Traffic Signs New MUTCD Criteria. Overview. Retroreflectivity briefing Rule-making efforts Final Rule summary Minimum Values Require maintenance methods future rulemaking Minimum pavement marking levels. Retroreflection Briefing.

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Minimum Retroreflectivity Levels for Traffic Signs New MUTCD Criteria

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  1. Minimum Retroreflectivity Levels for Traffic Signs New MUTCD Criteria

  2. Overview • Retroreflectivity briefing • Rule-making efforts • Final Rule summary • Minimum Values • Require maintenance methods future rulemaking • Minimum pavement marking levels

  3. Retroreflection Briefing

  4. Retroreflective Elements Glass spheres and microsized prisms are the current technologies used to make sign materials retroreflective

  5. Cone of Retroreflection Retroreflector Reflected light is brighter near light axis Reflected light gets dimmer as distance from light axis increases Light Source Direction

  6. Daytime Many cues available Driver task relatively easy Nighttime Few cues remain Task more difficult Nighttime Driving Retroreflectivity provides nighttime guidance

  7. Night Travel and Crashes Source: National Safety Council

  8. Retroreflectivity (cd/lx/m2) Time (years) Retroreflectivity Fades

  9. Background 1993 DOT Appropriations Act –“The Secretary of Transportation shall revise the MUTCD to include a standard for a minimum level of retroreflectivity that must be maintained for traffic signs and pavement markings which apply to all roads open to public travel.”

  10. Recent FHWA Research • Overhead guide signs and street name signs • FHWA-RD-03-082 • National sign workshops • FHWA-SA-03-002 • Updated sign levels • FHWA-RD-03-081 • Economic impacts report #2 • FHWA-HRT-07-042 • Sign retroreflectivity maintenance methods • FHWA-HRT-08-026

  11. Rule-Making Summary • 1985 – Advanced Notice of Proposed Amendment • 1992 - Congressional Directive • 1998 – AASHTO Resolution to FHWA • 2004 – Notice of Proposed Amendment • 2006 – Supplemental Notice of Proposed Amendment • 2007 - Final Rule

  12. Final Rule • Published on Dec 21, 2007 • Vol 72, No. 245 • Revision #2 of the 2003 Edition of the MUTCD • Effective Jan 22, 2008 Caltrans has 24 months to adopt as State regulation in the CA MUTCD by Jan 2, 2010

  13. Compliance Dates Jan 22, 2010 California MUTCD adoption deadline

  14. “Standard: Public agencies or officials having jurisdiction shall use an assessment or management method that is designed to maintain sign retroreflectivity at or above the minimum levels in Table 2A-3” New MUTCD LanguageSection 2A.09 Maintaining Minimum Retroreflectivity

  15. “Support: Compliance… is achieved by having a method in place and using the method to maintain the minimum levels established in Table 2A-3. Provided that… a method is being used, an agency would be in compliance… even if there are some individual signs that do not meet the… levels at a particular point in time. New MUTCD LanguageSection 2A.09 Maintaining Minimum Retroreflectivity

  16. MUTCD Table 2A-3

  17. All prismatic sheeting may be used for all signs. High Intensity Beaded (Type III) and Super Engineer Grade (Type II) may be used for all signs except for the white legend on overhead guide signs. Engineer Grade (Type I) may be used for all signs except for: a. the white legend on guide signs, b. the white legend on street name signs, and c. all warning signs. Sheeting Types (ASTM 4956-04)That Can Be Used:

  18. Even though a particular type of sheeting might initially meet the minimum retroreflectivity levels when new, it might quickly degrade to below the minimum retroreflectivity levels. The use of higher performance sheeting, even though it has a higher initial cost, might provide a better life-cycle cost for the agency. Sheeting Types That Can Be Used (cont.)

  19. “Guidance: …one or more of the following assessment or management methods should be used…” New MUTCD LanguageSection 2A.09 Maintaining Minimum Retroreflectivity

  20. Sign Maintenance Methods • Visual nighttime inspection • Measured sign retroreflectivity • Expected sign life • Blanket replacement • Control signs • Any combination of above • Other methods based on engineering studies

  21. Visual Inspection Method • Nighttime visual inspection by inspector trained on the procedures and the rule • Conduct on regular basis • Must use one of the options: • Calibration signs • Consistent parameters • Comparison panels

  22. Calibration Signs Option • “Calibrate” eyes with calibration signs • Calibration signs are near minimum retro • Evaluate signs compared to calibration signs

  23. Consistent Parameters Option • Inspection process replicates criteria used to develop minimum levels • Inspector – older driver (>60 years) • SUV type vehicle • Cutoff headlamps (properly aimed)

  24. Comparison Panels Option • Small panels at/near minimum retroreflectivity levels • Clipped to sign - viewed from distance • Replace sign if panel is brighter

  25. Measured Retroreflectivity Method • Measure signs with retroreflectometer • Procedure in ASTM E1709 • Average of 4 measurements • Compare average to minimum • Not all signs need to be measured • Measure marginal signs

  26. HandheldDevices

  27. Expected Sign Life Method • Determine expected life of sheeting types used in geographical area • End of life based on retro values in supplemental document • Set up replacement program that ensures individual signs are replaced prior to the end of service life expectancy • Periodic nighttime or instrument inspections to verify

  28. Indicating Sign Age • Stickers on front or back of sign to show when fabricated or installed

  29. Blanket Replacement Method • Divide agency into areas/corridors • Relate number of areas to replacement cycle (based on service life) • Replace all signs in an area/ corridor each replacement cycle • 10 yr life,  10 areas • Annual replacement in each area 7th year Replace all signs in this area during 1st year Replace all signs in this area during 3rd year 5th year

  30. Control Signs Method • Select signs to represent all signs in the field • Control signs in maintenance yard • Selected field signs (near HQ) • Monitor control signs • Replace all equivalent signs when control signs near minimum levels • Other methods determine replacement • Control signs need to adequately represent all signs in the field

  31. Combining Alternatives • Combination of methods • Use one or more of the methods together • Support and reinforce each other • Possibilities • Visual inspection to identify signs to be measured • Measured retro of control signs

  32. MUTCD Language

  33. Value of Inspection Inspectors can identify deficient signs that may not meet the minimum retroreflectivity levels

  34. Computer Sign Management • Agencies use computers to manage process • Track many elements • Help plan and budget • Computers track: • Sign type & sheeting • Location • Installation date • Expected sign life • Other factors

  35. Pavement Marking Retroreflectivity Standards- Status - • Initial research conducted in 1990s • Recent research just completed • Impacts report just completed • Workshops completed in summer 2007 • Input from public agencies • AASHTO & ATSSA submitted recommendations • FHWA beginning work on NPA • no target date

  36. Keep In Mind Congressional directive applies to signs and markings FHWA will establish MUTCD standards for pavement markings Solicited agency input for pavement markings in summer 2007 Looking for solutions Win-Win-Win for Drivers-Agencies-FHWA

  37. FHWA Supporting Material • FHWA Retro Web Site • 4-page summary • FAQs • Research Reports www.fhwa.dot.gov/retro

  38. Sign Sheeting ID Guide

  39. Summary • New regulation in place • Must use an assessment or management method in MUTCD • Must begin to make decisions now in order to meet compliance dates • Consider life-cycle costs, not just initial costs, when replacing signs

  40. Additional Information More information about sign and marking retroreflectivity can be found at FHWA: www.fhwa.dot.gov/retro ATSSA: www.retroreflectivity.net Expert Contact Information FHWA Retroreflectivity Team Leader Greg Schertz, 720-963-3764 FHWA Research Office Carl Andersen, 202-493-3366 FHWA Safety Office Matt Lupes, 202-366-6994

  41. Discussion / Questions

  42. Some Common Questions • What about.. • Engineering grade sheeting ? • Fluorescent signs ? • Blue and brown signs ? See FHWA FAQs for more questions: www.fhwa.dot.gov/retro

  43. Can I use Eng Grade Shtg? • Yes, but not for all signs • Where Engineering Grade cannot be used: • Yellow and orange signs • Legends on guide signs

  44. Fluorescent Signs • Fluorescent versions of sign colors may be used. Minimum retro is same as for non-fluorescent versions. • fluorescent yellow & fluorescent yellow-green • Use retro values for yellow • fluorescent orange • Use retro values for orange

  45. Blue & Brown Signs • Not yet included in minimum levels • Pending report contains recommended blue and brown levels • FHWA-HRT-08-029

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